fix: add session_updated event for realtime model

.changeset/real-squids-warn.md

@@ -0,0 +1,5 @@
+---
+"livekit-plugins-openai": patch
+---
+
+add session_updated event for RealtimeSession

livekit-plugins/livekit-plugins-openai/livekit/plugins/openai/realtime/__init__.py

@@ -11,6 +11,7 @@
     RealtimeOutput,
     RealtimeResponse,
     RealtimeSession,
+    RealtimeSessionOptions,
     RealtimeToolCall,
     ServerVadOptions,
 )
@@ -25,6 +26,7 @@
     "RealtimeSession",
     "RealtimeModel",
     "RealtimeError",
+    "RealtimeSessionOptions",
     "ServerVadOptions",
     "InputTranscriptionOptions",
     "ConversationItemCreated",

livekit-plugins/livekit-plugins-openai/livekit/plugins/openai/realtime/realtime_model.py

@@ -21,6 +21,7 @@
 
 EventTypes = Literal[
     "start_session",
+    "session_updated",
     "error",
     "input_speech_started",
     "input_speech_stopped",
@@ -151,18 +152,22 @@ class RealtimeError:
 
 
 @dataclass
-class _ModelOptions:
+class RealtimeSessionOptions:
     model: api_proto.OpenAIModel | str
     modalities: list[api_proto.Modality]
     instructions: str
     voice: api_proto.Voice
     input_audio_format: api_proto.AudioFormat
     output_audio_format: api_proto.AudioFormat
-    input_audio_transcription: InputTranscriptionOptions
-    turn_detection: ServerVadOptions
+    input_audio_transcription: InputTranscriptionOptions | None
+    turn_detection: ServerVadOptions | None
     tool_choice: api_proto.ToolChoice
     temperature: float
     max_response_output_tokens: int | Literal["inf"]
+
+
+@dataclass
+class _ModelOptions(RealtimeSessionOptions):
     api_key: str | None
     base_url: str
     entra_token: str | None
@@ -901,22 +906,27 @@ def session_update(
                 function_data["type"] = "function"
                 tools.append(function_data)
 
-        server_vad_opts: api_proto.ServerVad = {
-            "type": "server_vad",
-            "threshold": self._opts.turn_detection.threshold,
-            "prefix_padding_ms": self._opts.turn_detection.prefix_padding_ms,
-            "silence_duration_ms": self._opts.turn_detection.silence_duration_ms,
-        }
+        server_vad_opts: api_proto.ServerVad | None = None
+        if self._opts.turn_detection is not None:
+            server_vad_opts = {
+                "type": "server_vad",
+                "threshold": self._opts.turn_detection.threshold,
+                "prefix_padding_ms": self._opts.turn_detection.prefix_padding_ms,
+                "silence_duration_ms": self._opts.turn_detection.silence_duration_ms,
+            }
+        input_audio_transcription_opts: api_proto.InputAudioTranscription | None = None
+        if self._opts.input_audio_transcription is not None:
+            input_audio_transcription_opts = {
+                "model": self._opts.input_audio_transcription.model,
+            }
 
         session_data: api_proto.ClientEvent.SessionUpdateData = {
             "modalities": self._opts.modalities,
             "instructions": self._opts.instructions,
             "voice": self._opts.voice,
             "input_audio_format": self._opts.input_audio_format,
             "output_audio_format": self._opts.output_audio_format,
-            "input_audio_transcription": {
-                "model": self._opts.input_audio_transcription.model,
-            },
+            "input_audio_transcription": input_audio_transcription_opts,
             "turn_detection": server_vad_opts,
             "tools": tools,
             "tool_choice": self._opts.tool_choice,
@@ -1103,6 +1113,8 @@ async def _recv_task():
 
                     if event == "session.created":
                         self._handle_session_created(data)
+                    if event == "session.updated":
+                        self._handle_session_updated(data)
                     elif event == "error":
                         self._handle_error(data)
                     elif event == "input_audio_buffer.speech_started":
@@ -1171,6 +1183,42 @@ def _handle_session_created(
     ):
         self._session_id = session_created["session"]["id"]
 
+    def _handle_session_updated(
+        self, session_updated: api_proto.ServerEvent.SessionUpdated
+    ):
+        session = session_updated["session"]
+        if session["turn_detection"] is None:
+            turn_detection = None
+        else:
+            turn_detection = ServerVadOptions(
+                threshold=session["turn_detection"]["threshold"],
+                prefix_padding_ms=session["turn_detection"]["prefix_padding_ms"],
+                silence_duration_ms=session["turn_detection"]["silence_duration_ms"],
+            )
+        if session["input_audio_transcription"] is None:
+            input_audio_transcription = None
+        else:
+            input_audio_transcription = InputTranscriptionOptions(
+                model=session["input_audio_transcription"]["model"],
+            )
+
+        self.emit(
+            "session_updated",
+            RealtimeSessionOptions(
+                model=session["model"],
+                modalities=session["modalities"],
+                instructions=session["instructions"],
+                voice=session["voice"],
+                input_audio_format=session["input_audio_format"],
+                output_audio_format=session["output_audio_format"],
+                input_audio_transcription=input_audio_transcription,
+                turn_detection=turn_detection,
+                tool_choice=session["tool_choice"],
+                temperature=session["temperature"],
+                max_response_output_tokens=session["max_response_output_tokens"],
+            ),
+        )
+
     def _handle_error(self, error: api_proto.ServerEvent.Error):
         logger.error(
             "OpenAI S2S error %s",